System and method for joint resurfacing and repair

ABSTRACT

An implant resection system for preparing an implant site to replace a defect in an articular surface of a first bone includes a first guide configured to be coupled generally to the first bone. The first guide includes a body portion defining a channel configured to receive a pin, wherein the pin is configured to penetrate and form a longitudinally disposed bore within the first bone. The implant resection system further includes a second guide configured to be coupled generally perpendicular to the first bone proximate to the defect by way of the bore. The second guide includes a drill bit configured to form an excision site through a portion of the articular surface in preparation of receipt of an implant.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional PatentApplication Ser. No. 61/667,562, filed on Jul. 3, 2012, which is fullyincorporated herein by reference.

FIELD

This disclosure relates to the repair of defects that occur on thesurface of bones, and, more particularly, devices and methods for therepair of defects that occur in articular cartilage on the surface ofbones of the tibiofemoral joint, or knee joint.

BACKGROUND

Articular cartilage, found at the ends of articulating bone in the body,is typically composed of hyaline cartilage, which has many uniqueproperties that allow it to function effectively as a smooth andlubricious load-bearing surface. When injured, however, hyalinecartilage cells are not typically replaced by new hyaline cartilagecells. Healing is dependent upon the occurrence of bleeding from theunderlying bone and formation of scar or reparative cartilage calledfibrocartilage. While similar, fibrocartilage does not possess the sameunique aspects of native hyaline cartilage and tends to be far lessdurable.

In some cases, it may be necessary or desirable to repair the damagedarticular cartilage using an implant. While implants may be successfullyused, the implant should have a shape substantially corresponding to thearticular cartilage proximate the area where the implant is to be placedin order to maximize the patient's comfort, minimize damage tosurrounding areas, and maximize the functional life of the implant.

BRIEF DESCRIPTION OF THE DRAWINGS

Features and advantages of the present invention are set forth bydescription of embodiments consistent with the present invention, whichdescription should be considered in conjunction with the accompanyingdrawings wherein:

FIG. 1 is a schematic diagram illustrating an incision proximate theknee;

FIG. 2 is a perspective view illustrating one embodiment of a guidecoupled to the tibia consistent with the present disclosure;

FIG. 3 is a perspective view illustrating pins advanced within the guideand into the tibia consistent with the present disclosure;

FIG. 4 is a perspective view illustrating a drill bit advanced onto oneof the pins consistent with the present disclosure;

FIG. 5 is a perspective view of one embodiment of a drill bit consistentwith the present disclosure;

FIG. 6 illustrates one embodiment of a first and second excision siteformed on the tibial articular surface using the drill bit consistentwith the present disclosure;

FIGS. 7 and 8 are perspective views illustrating one embodiment of atibial implant coupled to the first and second excision site of thetibial articular surface consistent with the present disclosure;

FIG. 9 is a schematic diagram illustrating an incision proximate theknee;

FIG. 10 is a perspective view illustrating one embodiment of a firstguide coupled to the femur and having a pin advanced within the guideand into the femur consistent with the present disclosure;

FIGS. 11 and 12 are side and perspective views of one embodiment of asurface reamer consistent with the present disclosure;

FIGS. 13 and 14 are perspective views of the surface reamer of FIGS. 11and 12 aligned with the pin and engaging the femur consistent with thepresent disclosure;

FIG. 15 is a perspective view illustrating one embodiment of a secondguide configured to be coupled to the femur consistent with the presentdisclosure;

FIG. 16 is a side plan view of one embodiment of a second guide coupledto the femur as generally shown in FIG. 15 consistent with the presentdisclosure;

FIG. 17 is a front view of the second guide coupled to the femur in afirst position consistent with the present disclosure;

FIG. 18 is a front view of the second guide coupled to the femur andmoving from the first position to a second position;

FIGS. 19 and 20 are front and side views of one embodiment of first andsecond excision sites formed on an articular surface of a femoralcondyle using the reamer and second guide consistent with the presentdisclosure;

FIGS. 21-23 are side, frontal and perspective views of one embodiment ofa femoral implant consistent with the present disclosure; and

FIGS. 24A and 24B are side views of the femoral implant of FIGS. 21-23aligned with and coupled to first and second excision sites of thearticular surface of the femoral condyle consistent with the presentdisclosure.

DETAILED DESCRIPTION

By way of summary, one embodiment of the present disclosure may featurea system and method for repairing a portion of the articular surfaceproximate to a defect. While the present disclosure will be described interms of a system and method for repairing a portion of the tibial andfemoral articular surfaces, it should be understood that the system andmethod may be used to repair other articular surfaces (such as, but notlimited to, humeral articular surfaces and the like).

The system and method may include securing a guide defining one or morepassageways to a portion of the tibia (e.g., immediately below thetibial articular surface) proximate to the defect. The passageways maydefine a generally cylindrical core pathway for one or more alignmentpins to pass through. When the alignment pins are secured to the tibia,a first truncated cylindrical excision site may be formed in thearticular surface and/or bone beneath the articular surface by advancinga drill bit (i.e., a coring drill bit) along the alignment pins. Thedrill may have a diameter large enough to remove a portion of thearticular surface as it is advanced through the guide and into thearticular surface. Additional truncated cylindrical excision sites mayalso be formed. One or more of the additional truncated cylindricalexcision sites may partially overlap with adjacent truncated cylindricalexcision sites.

The guide and/or the drill may include a depth feature configured tocontrol the depth of the truncated cylindrical excision site formed inthe articular surface/bone of the tibia. The depth feature may preventthe drill from being advanced too far, thereby preventing the drill fromaccidentally damaging any structures proximate to the excision sites(e.g., nerves). The system and method may also include a tibial implanthaving a load bearing surface having a surface contour/geometry based onthe surface contour/geometry of the patient's original removed articularsurface of the tibia. For example, the surface contour/geometry of theload bearing surface may be based on one or more measurements taken ofthe patient's original articular surface. The implant may also feature abone facing or distal surface having a surface contour/geometryconfigured to be received in the truncated cylindrical excision sites.

The system and method may further include a first guide for aligning andsecuring a second drill guide to a portion of the femur (e.g., lateralor medial femoral condyle) proximate to the defect. The first guide maydefine a channel for receiving and retaining a pin. Upon advancing thepin through the channel of the first guide in a direction towards thefemur, the pin may engage and pierce the bone to form a bore within aportion of the femur (e.g., femoral condyle). The system and method mayfurther include securing the second drill guide defining one or morepassageways to a portion of the femur (e.g. femoral condyle). At leastone of the passageways may define a generally cylindrical core pathwayfor a support rod to pass therethrough and secure the second drill guideto the femur. Another passageway may define a generally cylindrical corepathway for a drill bit (i.e., a router drill bit). The support rod mayserve as an axis about which the drill bit may rotate. An excision sitemay be formed in the articular surface of a femoral condyle and/or bonebeneath the articular surface by rotating the drill guide, and the drillbit, about the support rod. The drill may have a diameter large enoughto remove a portion of the articular surface as it is rotated about thesupport rod and into the articular surface.

The second drill guide and/or the drill may include a depth featureconfigured to control the depth of the excision site formed in thearticular surface/bone of the femoral condyle of the femur. The depthfeature may prevent the drill from being advanced too far, therebypreventing the drill from accidentally damaging any structures proximateto the excision site (e.g., nerves). The system and method may alsoinclude a femoral condyle implant having a load bearing surface having asurface contour/geometry based on the surface contour/geometry of thepatient's original removed articular surface of the femur. For example,the surface contour/geometry of the load bearing surface may be based onone or more measurements taken of the patient's original articularsurface. The implant may also feature a bone facing or distal surfacehaving a surface contour/geometry configured to be received in theexcision site.

Turning now to FIG. 1, a tibia 10 is generally illustrated. As may beappreciated, the tibial articular surface 12 may include a tibialplateau comprising a plurality of concaved surfaces 14 a, 14 bconfigured to articulate with the femoral condyles (not shown forclarity). It may be further appreciated that the tibial articularsurface 12 may include additional concaved surfaces not shown for thesake of clarity. One or more of the concaved surfaces (e.g., concavedsurface 14 a) may include a defect 13 in the tibial articular surface 12to be repaired. On the distal side of the tibia 10, a nerve bundle 16 islocated. As described herein, the system and method according to oneembodiment of the present disclosure may be configured to avoid damagingthe nerve bundle when forming the excision site(s).

For illustrative purposes, the following will describe a system andmethod for preparing an implant site on the tibial articular surfaceincluding two partially overlapping truncated cylindrical excision sitesand an implant configured to fit therein. As may be appreciated, thesystem and method according to the present disclosure may be used toform an implant site having greater than or fewer than two partiallyoverlapping truncated cylindrical excision sites. As will be evidentfrom the following description, the truncated cylindrical excision sitesmay be formed by drilling along the anterior-posterior plane (i.e., froman anterior face of the tibia 10 and extending generally towards theposterior face of the tibia 10).

Turning now to FIG. 2, one embodiment of a guide 18 secured to the tibia10 is generally illustrated consistent with the present disclosure. Theguide 18 may include a jig 20 and a spoon 22. The jig 20 may include abody portion 24 and a handle portion 26 extending therefrom. The bodyportion 24 may define at least two passageways 28 a, 28 b. Thepassageways 28 a, 28 b may each define a generally cylindrical pathwayfor alignment pins 30 a, 30 b. The alignment pins 30 a, 30 b may beadvanced through the passageways 28 a, 28 b into the tibia 10, asgenerally illustrated in FIG. 3. The alignment pins 30 a, 30 b mayinclude a depth feature 32 a, 32 b configured to control the depth ofthe pins 30 a, 30 b in the bone 10 (i.e., to prevent the pins 30 a, 30 bfrom being set too deep or too shallow into the bone 10). The depthfeature 32 a, 32 b may comprise an indicia (e.g., but not limited to, alaser marking, groove, or the like) which may be aligned with theproximal end of the passageways 28 a, 28 b. The alignment pins 30 a, 30b may be configured to generally align a drill bit with a desired are ofbone 10 to be cut and to maintain alignment of the drill bit duringexcision of the bone 10, as described in greater detail herein.

The position of the jig 20 (and in particular, the passageways 28 a, 28b) may be set based on, at least in part, the spoon 22. In particular,the spoon 22 may include a generally convex base portion 34 having asurface contour substantially corresponding to the curvature of theconcaved surface 14 a being repaired (e.g., the concaved surface 14 awhich has the defect 13). An upper portion 36 of the spoon 22 may have agenerally concaved surface (e.g., generally corresponding to thecurvature of the concaved surface 14 a being repaired). The spoon 22 mayhave a cross-sectional thickness configured to facilitate advancement ofthe spoon 22 between the tibial articular surface 12 and the femoralcondyles (shown in FIG. 9, for example). For example, thecross-sectional thickness of the spoon 22 may be selected to providesufficient rigidity to align the jig 20 relative to the tibial articularsurface 12 (and in particular, the defect 13 on the concaved surface 14a) while also minimizing the required separation between the tibia 10and the femur.

The spoon 22 may be an integral component of the jig 20 (e.g., a unitaryor single one-piece structure) or may be configured to be releasablycoupled to the jig 20. For example, in the illustrated embodiment, thespoon 22 may include an arm portion 38 configured to extend generallyoutwardly from a distal face 40 (e.g., a bone facing surface) of the jig20. As shown, the body 24 of the jig 20 may include a channel 42 shapedand/or sized to receive and retain a portion of the arm 38. The size andshape of the arm portion 38 may be configured to allow a portion of thedistal face 40 to be disposed proximate to the perimeter (e.g.,proximate to the meniscus 44) when the spoon 22 is disposed on theconcaved surface 14 a such that the first and second passageways 28 a,28 b partially overlap with the tibial articular surface 12.

In practice, the guide 18 may be positioned relative to the defect 13 onthe concaved surface 14 a by advancing the spoon 22 between the tibialarticular surface 12 and the femur such that the base portion 34 of thespoon 22 is disposed over at least a portion of the defect 13 on thetibial articular surface 12. The spoon 22 may be advanced until thedistal face 40 of the jig 20 generally abuts against a portion of thetibia 10 (e.g., proximate to the meniscus 44). The size and shape of thebase portion 34 as well as the arm portion 38/distal face 40 may beconfigured to generally center the spoon 22 within the concaved surface14 a. Once the spoon 22 is positioned over the defect 13, the alignmentpins 30 a, 30 b may be advanced through the passageways 28 a, 28 b andinto the tibia 10, as shown in FIG. 3. It should be noted that internalfeatures and/or surfaces are illustrated in phantom in FIG. 3. As shown,distal ends 31 a, 31 b of the alignment pins 30 a, 30 b may engage andpierce the bone 10, thereby securely coupling the alignment pins 30 a,30 b to the bone 10.

Turning now to FIG. 4, upon advancing the alignment pins 30 a, 30 b intothe bone 10, the guide 18 may be removed from the bone 10. As such, thealignment pins 30 a, 30 b may remain within the bone 10 and may beconfigured to provide alignment of a drill bit with the bone 10 to formfirst and second excision sites. In the illustrated embodiment, abushing 46 may be advanced along the alignment pins 30 a, 30 b andagainst the bone 10. For example, the bushing 46 may include alongitudinally disposed passageway 48 shaped and/or sized to receive atleast the first alignment pin 28 a. The bushing 46 may be advanced alongthe alignment pin 28 a until the bushing 46 engages against (e.g.,abuts) a portion of the tibia 10 (e.g., proximate to the meniscus 44). Acannulated drill 50 may then be advanced over the bushing 46 and thealignment pin 28 a and into the bone 10 to form a first truncatedcylindrical excision site (shown in FIG. 6). Upon forming the firstexcision site, the drill 50 and bushing 46 may be removed from the firstalignment pin 28 a and then placed over and advanced along the secondalignment pin 28 b to form a second truncated cylindrical excision sitein the bone 10 (shown in FIG. 6).

One embodiment of a cannulated drill 50 is generally illustrated in FIG.5. The cannulated drill 50 may feature a core drill bit 52 having abarrel portion 53 and optionally a shank portion 54 extending from thebarrel portion 53. The shank portion 54 may include a multi-facetedproximal end configured to be secured to a drill (e.g., a hand drill,electric drill, pneumatic drill or the like). Alternatively, a proximalend of the core drill bit 52 may be directly coupled to the drill.

The core drill bit 52 may include a cutting surface 56 (for example,comprising a plurality of cutting teeth 57) disposed about a distal endof the barrel portion 53. The cutting surface 56 may be evenly disposedaround the generally circular distal end of the barrel portion 53. Thebarrel portion 53 may define a core cavity 58 configured to receive theremoved portion of the tibial articular surface 12 and bone 10. As maybe appreciated, the only portion of the tibial articular surface 12 andbone 10 that is cut by the core drill bit 50 corresponds to thethickness of the cutting surface 56, which itself is a function of thewall thickness of the barrel 53. As such, these thicknesses may beselected to remove the least amount of material while also providing thenecessary rigidity and/or strength to the core drill bit 50.

The core drill bit 52 may optionally feature one or more windows 60disposed along the length of the barrel portion 53. The window 60 mayallow air, fluid, and cutting chips to exit the barrel portion 53. Inaddition, the window 60 may also allow the user to align the core drillbit 52 with the alignment pins 30 a, 30 b to control the depth of theexcision site (i.e., the length of the excision site as measured acrossthe tibial articular surface 12).

As shown, the core drill bit 52, particularly the barrel portion 53, maybe shaped and/or sized to receive the bushing 46 configured facilitatealignment of the core drill bit 52 as the core drill bit 52 is advancedinto the tibial articular surface 12 and bone 10. The bushing 46 may betranslatably disposed along the longitudinal axis of the core drill bit52 and may include a passageway 48 configured to receive the alignmentpins 30 a, 30 b. For example, the bushing 46 may be initially locatednear the distal end of the barrel portion 53. As the core drill bit 52is advanced towards the bone 10, an alignment pin 30 a, 30 b may bereceived in the passageway 48 and the bushing 46 may translate towardsthe proximal end.

As the drill bit 50 is advanced towards the bone 10, a portion of thecutting surface 56 may engage the tibial articular surface 12 and/or thebone 10, thereby forming a truncated cylindrical excision site. Once thedrill bit 50 has been advanced to create the first excision site, thesecond truncated cylindrical excision site may be formed. For example,the bushing 46 and drill bit 50 may be removed from the first alignmentpin 30 a and placed on the second alignment pin 30 b and the drill bit50 may be advanced toward the bone 10 in a manner similar to thatdescribed herein. Although the same bushing 46 and drill bit 50 aredescribed as being used to create the first and second excision sites, asecond bushing and drill bit may be used with the second alignment pin30 b to create the second excision site, wherein the first and seconddrill bits may have the same or different outer diameters.

FIG. 6 generally illustrates one embodiment of the first and the secondtruncated cylindrical excision sites 62 a, 62 b corresponding to thedrill bit 50 and the first and second alignment pins 30 a, 30 b.Although shown as being truncated, in other embodiments, the first andsecond excision sites 62 a, 62 b may be separated by a distancegenerally perpendicular to the longitudinal axes of the first and secondalignment pins 30 a, 30 such that the first and the second truncatedcylindrical excision sites 62 a, 62 b do not overlap.

The resulting implant site may therefore include the first and secondtruncated cylindrical excision sites 62 a, 62 b, wherein the first andsecond truncated cylindrical excision sites 62 a, 62 b partially overlapwith one another. The truncated cylindrical excision sites 62 a, 62 bmay be centered/revolved around the alignment pins 30 a, 30 b and mayextend along the articular surface 12 generally along theanterior-posterior plane. For example, the truncated cylindricalexcision sites 62 a, 62 b may extend from the anterior face of thetibial articular surface 12 generally towards the posterior face. Theimplant site may therefore include a base portion 64 including twooverlapping truncated cylindrical extensions or scallops defined by thetwo excision sites 62 a, 62 b. The resulting implant site therefore maygenerally eliminate/reduce the occurrence of 90 degree cuts andtherefore more evenly distribute loads/forces to the bone 10 compared atraditional 90 degree notch cut.

The truncated cylindrical excision sites 62 a, 62 b have beenillustrated extending partially across the tibial articular surface 12(i.e., one or more of the truncated cylindrical excision sites 62 a, 62b do not extend completely across the articular surface 12 thus leavinga portion 66 of the tibial articular surface 12 and/or bone 10remaining). This embodiment may be particularly beneficial since itfurther minimizes the potential for accidentally damaging the nervebundle. However, the system and method according to the presentdisclosure may also allow for one or more of the truncated cylindricalexcision sites 62 a, 62 b to extend completely across the articularsurface 12.

Turning now to FIGS. 7 and 8, one embodiment of an implant 70 coupled tothe first and second excision sites of the tibia consistent with thepresent disclosure is generally illustrated. The implant 70 may includea load bearing surface 72 and a bone facing or distal surface 74. Theload bearing surface 72 may have a surface contour/geometrysubstantially corresponding to the contour/geometry of the removedtibial articular surface 12 proximate the defect 13. Thecontour/geometry of the load bearing surface may be based on a pluralityof measurement take of the patient's tibial articular surface 12.

The bone facing surface 74 may have an overall contour/geometrygenerally corresponding to the contour/geometry of the base portion 64of the first and second truncated cylindrical excision sites 62 a, 62 band the removed bone 10. Optionally, the bone facing surface 74 mayinclude one or more relief cavities, pockets and/or cross-cuts 76configured to enhance securing the implant 70 to the bone 10 within thetruncated cylindrical excision sites 62 a, 62 b. The relief cavities 76may be configured to allow bone regrowth around a portion of the implant70 and/or promote cement adhesion. As shown, the implant 70 may includea generally unitary structure (i.e., the implant 70 may be a solid,single-piece component). In one embodiment, the implant 70 may be madefrom ultra-high molecular weight polyethylene (UHMWPE) material.Additionally (or alternatively), the implant 70 may be made from amaterial based on donor tissue and/or synthetic bone and cartilageconstruct. For example, the implant 70 may include a ceramic porous baselayer that defining the bone facing surface 74 and a collagen materialdisposed on a top portion thereof and defining the load bearing surface72.

In other embodiments, the implant 70 may include multiple portionsconfigured to be coupled together. Additionally, the implant 70 mayoptionally comprise one or more keels, tails, protrusions or the like,that extend generally downwardly from the bone facing surface 74 andaway from the load bearing surface 72. The keels, tails, or protrusionsmay be configured to engage a corresponding notch (not shown) formed inthe base portion 64 of the truncated cylindrical excision sites 62 a, 62b.

As may be appreciated from FIGS. 7 and 8, an implant consistent with atleast one embodiment of the present disclosure may have a non-planarload bearing surface 72. While some known tibial implants have had agenerally planar or flat load bearing surface, an implant consistentwith at least one embodiment of the present disclosure may have aconcaved geometry which may better approximate the geometry of thepatient's removed tibial articular surface 12.

Turning now to FIG. 9, a knee joint 100 is generally illustrated. Morespecifically, the tibiofemoral components (i.e. tibia 10 and femur 102)are shown. The femur 102 may generally include femoral articular surface104 that may include femoral condyles 106 a, 106 b configured toarticulate with the tibial articular surface 12 and concaved surfaces 14a, 14 b of the tibia 10. It may be further appreciated that the kneejoint 100 include a patella (not shown for the sake of clarity). One ofthe femoral condyles (e.g., condyle 106) may include a defect 108 in thearticular surface 104 to be repaired.

For illustrative purposes, the following will describe a system andmethod for preparing an implant site on the articular surface of afemoral condyle including an excision site and an implant configured tofit therein. As will be evident from the following description, theexcision sites may be formed by drilling along the horizontal plane of afemoral condyle (i.e., from lateral to medial and/or vice versa).

Turning now to FIG. 10, one embodiment of a first guide 110 secured to afemoral condyle 106 a of the femur 102 is generally illustratedconsistent with the present disclosure. The first guide 110 may includea jig 112 and a spoon 114. The jig 112 may include a body portion 116including at least one channel 118 longitudinally disposed on a portionthereof. The channel 118 may extend from a proximal end 119 a to adistal end 119 b of the body 116. The channel 118 may be shaped and/orsized to receive and retain a pin 120. As shown, the pin 120 may beadvanced through the channel 118 and into the femur 102 (e.g. femoralcondyle 106 a). The pin 120 may further include a distal end 121configured to engage and pierce the bone 102. The pin 120 may furtherinclude a depth feature 122 configured to control the depth of the pin120 into the bone 102 (i.e., to prevent the pin 120 from being set toodeep or too shallow into the bone 102). The depth feature 121 mayinclude an indicia (e.g., but not limited to, a laser marking, groove,or the like) which may be aligned with the proximal end 119 a of thebody 116 of the first guide 110.

The position of the jig 112 (and in particular, the channel 118) may beset based on, at least in part, the spoon 114. As shown, the spoon 114may include a generally convex base portion 124 having a surface contoursubstantially corresponding to the curvature of a concaved surfaceopposing the associated femoral condyle being repaired (e.g., theconcaved surface 14 a opposing the femoral condyle 106 a which has thedefect 108). An upper portion 126 of the spoon 114 may have a generallyconcaved surface (e.g., generally corresponding to the curvature of thefemoral condyle 106 a surface being repaired). The spoon 112 may have across-sectional thickness configured to facilitate advancement of thespoon 114 between the tibial articular surface 12 and the femoralcondyles 106 a, 106 b. For example, the cross-sectional thickness of thespoon 112 may be selected to provide sufficient rigidity to align thejig 112 relative to the tibial articular surface 12 and one of thefemoral condyles (and in particular, the defect 108 on the femoralcondyle 106 a) while also minimizing the required separation between thetibia 10 and the femur 102.

The spoon 112 may be an integral component of the jig 112 (e.g., aunitary or single one-piece structure) or may be configured to bereleasably coupled to the jig 112. For example, in the illustratedembodiment, the spoon 114 may include an arm portion 128 configured toextend generally outwardly from the distal end 119 b of the body 116 ofthe jig 112. As shown, the body 116 of the jig 112 may include a channel130 shaped and/or sized to receive and retain a portion of the arm 128.In the illustrated embodiment, the jig 112 may further include analignment member 132 extending from the distal end 119 b of the body116. The alignment member 132 may include a distal face 134 (e.g., abone facing surface). The distal face 134 may have a generally concavedsurface (e.g., generally corresponding to the curvature of the femoralcondyle 106 a surface being repaired). The size and shape of the armportion 128 may allow a portion of the distal face 134 of the alignmentmember 132 to be disposed proximate to the femoral condyle 106 a whenthe spoon 114 is disposed between the tibial articular surface 12 andthe femoral condyle 106 a (and in particular, on the concaved surface 14a and the femoral condyle 106 a) such that the channel 118 is alignedwith a portion of the articular surface of the femoral condyle 106 a.The alignment member 132 may further include a passageway 136. Thepassageway 136 may be shaped and/or sized to allow the pin 120 to passthrough upon advancement towards the bone 102. The passageway 136 mayfurther provide a user with visual observation of the penetration site137 of the pin 120 into the bone 102.

In practice, the first guide 110 may be positioned relative to thedefect 108 on articular surface of the femoral condyle 106 a byadvancing the spoon 114 between the tibial articular surface 12 and thefemoral condyle 106 a such that the upper portion 126 of the spoon 114and/or distal face 134 of the alignment member 132 is disposed over atleast a portion of the defect 108 on the articular surface of thefemoral condyle 106 a. The spoon 114 may be advanced until the distalface 134 of the alignment member 132 generally abuts against a portionof the femoral condyle 106 a. The size and shape of the base portion 124and upper portion 126 of the spoon 112, as well as the arm portion128/distal face 134, may be configured to generally center the spoon 112within the concaved surface 14 a of the tibia 10 and associated femoralcondyle 106 a. Once the spoon 114 is positioned, the pin 120 may beadvanced along the channel 118 and through the passageway 136 and intothe femur 102. As shown, the distal end 121 of the pin 120 may beconfigured to engage and pierce the bone 102 to create a substantiallylongitudinal bore within the bone 102 (shown in FIG. 15).

Turning now to FIGS. 11 and 12, side and perspective views of a surfacereamer 140 consistent with the present disclosure is generallyillustrated. As described in greater detail herein, the surface reamer140 may be configured to remove a portion of bone and form a firstexcision site 141 (shown in FIG. 15) on the articular surface 104 of thefemoral condyle 106 a adjacent the pin 120. As shown, the surface reamer140 includes a cannulated body 142 having a proximal end 144 and anopposing distal end 146. The distal end 146 includes one or more cuttingsurfaces 148 configured to remove bone and the proximal end 144 isconfigured to be coupled to a drill 150 (e.g., a hand drill, electricdrill, pneumatic drill or the like).

The drill 150 may be configured to drive (e.g. rotate) the distal end146 and, in turn, the cutting surfaces 148 of the surface reamer 140 tofacilitate bone removal when the cutting surfaces 148 engage bone of thefemur 102. As shown, the body 142 of the surface reamer 140 iscannulated (e.g. include a passageway 152 extending the length thereof),allowing the surface reamer 140 to be disposed over the alignment pin120 along a reference axis A.

FIGS. 13 and 14 are perspective views of the surface reamer 140 alignedwith the pin 120 and engaging a portion of the femoral condyle 106 aconsistent with the present disclosure. As shown, the surface reamer 140may be advanced over the pin 120 along a reference axis A. The surfacereamer 140 may include an indicia (for example, an opening/window, lasermarker, or the like) configured to control the depth of the firstexcision site to be formed. For example, the indicia may include a lasermarking or the like configured to be aligned with the articular surface104. The indicia may also include an opening/window or the like whichmay be aligned with an indicia on the pin 120. The cutting surfaces 148may optionally be positioned about the surface reamer 140 to leave morematerial proximate the pin 120 along the reference axis A to facilitateremoval and insertion of devices further along the method.

The surface reamer 140 may have a specific geometry and/or pattern tominimize vibrations and improve tactile feel while negotiating aninterrupted cut on the articular surface 104 of the femoral condyle 106a. The diameter of the surface reamer 140, including the diameter of theproximal end 146, may be selected based on, for example, the desiredsize of implant to be positioned thereon. Once the first excision site141 has been formed about the reference axis A, the surface reamer 140may be removed from the pin 120.

Turning now to FIG. 15, a perspective view of one embodiment of a secondguide 154 configured to be coupled to the femur 102 is generallyillustrated consistent with the present disclosure. As shown, the secondguide 154 may include a jig 156 having a body portion 158 including ahandle 160 disposed at one end and first and second passageways 162 a,162 b defined at an opposing end. The first and second passageways 162a, 162 b may each define a generally cylindrical core pathway. The firstpassageway 162 a may be shaped and/or sized to receive and retain asupport rod 164 therein. As previously described, advancement of the pin120 into the bone 102 may form a substantially longitudinal bore 153within the bone 102 (particularly the femoral condyle 106 a having thedefect 108 to be repaired). The support rod 164 may be configured tosecure the second guide 154 to the femoral condyle 106 a. Morespecifically, a portion of the support rod 164 may be received within aportion of the bore 153 formed in the femoral condyle 106 a and may besecurely coupled to the bone 102. The second passageway 162 b may beshaped and/or sized to receive and retain a drill bit 166 which may beused to form an excision site on the articular surface of the femoralcondyle 106 a.

As described in greater detail herein, the first and the secondpassageways 162 a, 162 b may be offset relative to each other (i.e., thefirst and the second passageways 162 a, 162 b may be separated by adistance generally perpendicular to the longitudinal axes of the firstand the second passageways 162 a, 162 b, such that the depth of excisionsite formed by the drill bit in the articular surface of the femoralcondyle 106 a may be dictated by such a distance between the first andsecond passageways 162 a, 162 b).

As shown in FIG. 16, the second guide 154 may be secured to the femur102 by the support rod 164. In the illustrated embodiment, the pin 120may be removed from the femur 102, leaving the bore 153 exposed and thesupport rod 164 may include a distal end 168 configured to be driveninto the bore 153 and securely couple the support rod 164 within thebone 102. In other embodiments, the pin 120 may remain secured withinthe bore 153 and the support rod 164 may be configured to be disposedover the pin 120 (e.g. cannulated) and secured within the bone 102.

As shown, the support rod 164 may serve as an axis (generally alignedwith reference axis A) about which the jig 156, and ultimately the drillbit 166, may rotate, as described in greater detail herein. Uponadvancing the support rod 164 into the bore 153 and thereby securelycoupling the second guide 154 to the femoral condyle 106 a, a portion ofthe drill bit 166 may be positioned adjacent a portion of the articularsurface of the femoral condyle 106 a having the defect 108 to berepaired. More specifically, the drill bit 166 may include a cuttingsurface 169 positioned adjacent the articular surface and configured toform a second excision site in the articular surface of the femoralcondyle 106 a and/or bone beneath the articular surface. The drill bit166 may further include a shank portion 170. The shank portion 170 mayinclude a multi-faceted proximal end configured to be secured to a drill(e.g., a hand drill, electric drill, pneumatic drill or the like).Alternatively, a proximal end of the drill bit 166 may be directlycoupled to the drill.

FIGS. 17 and 18 are frontal views of the second guide 154 coupled to thefemur 102 by way of the support rod 164. More specifically, FIG. 17illustrates the second guide 154 in a first position and FIG. 18illustrates the second guide 154 moving from the first position to asecond position and forming a second excision site 176 in the femur 102.As previously described, the support rod 164 may serve as an axis aboutwhich the jig 156, including the drill bit 166, may rotate. When thesecond guide 154 is in the first position, as shown in FIG. 17, thedrill bit 166 is adjacent a portion of femoral condyle 106 a and may notdirectly engage the femoral condyle 106 a. The second excision site 176may be formed in the articular surface of the femoral condyle 106 aand/or bone beneath by moving the second guide 154 from the firstposition to the second position, as shown in FIG. 18. More specifically,a user may use the handle 160 of the jig 156 to rotate the jig 156 fromthe first position to the second position. As the jig 156 is rotatedabout the support rod 164, as indicated by arrow 172, the drill bit 166may also rotate about the support rod 164, as indicated by arrow 174,thereby causing the drill bit 166 to advance towards the femoral condyle106 a. As the drill bit 166 advances towards the femoral condyle 106 a,a portion of the cutting surface 169 of the drill bit 166 engages thearticular surface of the femoral condyle 106 a and/or the bone beneath,thereby forming the second excision site 176. As the jig 156 continuesto rotate about the support rod 164, the drill bit 166 further advancestowards and engages uncut articular surface and/or bone of the femoralcondyle 106 a to form the second excision site 162. The user may stoprotating the jig 156 once the desired size and/or shape of the secondexcision site 176 has been formed.

As may be appreciated, the only portion of the femoral condyle 106 a,including articular surface and/or bone beneath, that is cut by thedrill bit 166 corresponds to the distance D between the support rod 164and the drill bit 166, and the length L of the cutting surface 169 ofthe drill bit 166. As generally understood, the distance D may varydepending on the desired depth in the anterior-posterior plane (i.e.,from the posterior surface of the femur 102 and extending generallytowards the anterior surface of the femur 102). Similarly, the length Lmay vary depending on the desired depth in the superior-inferior plane(i.e. from the inferior, or lower extremity, portion of the femur 102and extending generally towards the superior, or upper extremity,portion of the femur 102). As such, the distance D and length L may eachbe selected to remove the least amount of material so as to control thedepth of the second excision site 176 (i.e., the length of the secondexcision site 176 as measured across the articular surface of thefemoral condyle 106 a in both the anterior-posterior andsuperior-inferior planes).

FIGS. 19 and 20 generally illustrate one embodiment of the first andsecond excision sites 141, 174 corresponding to the surface reamer 140and drill bit 166, respectively. As shown, the first excision site 141may extend along a portion of the articular surface of the femoralcondyle 106 a proximate the longitudinal bore 153 and generally alongthe superior-inferior and medial-lateral planes. For example, the firstexcision site 141 may extend from the inferior portion of the femur 102to the superior portion. The second excision site 176 may extend alongthe articular surface of the femoral condyle 106 a generally along theanterior-posterior and superior-inferior planes. For example, the secondexcision site 176 may extend from the posterior face of the femoralcondyle 106 a generally towards the anterior face and from the inferiorportion of the femur 102 to the superior portion. The first and secondexcision sites 141, 176 may collectively serve as an implant site for afemoral condyle implant to be received within, as described in greaterdetail herein.

As shown, the first excision site 141 includes a base portion 177configured to receive a portion of the femoral condyle implant.Similarly, the second excision site 176 includes a base portion 178configured to receive a portion of the femoral condyle implant. Thesecond excision site 176 has been illustrated extending partially acrossa portion of the femoral condyle 106 a (i.e., the second excision site176 does not extend completely across the articular surface of thefemoral condyle 106 a, thus leaving a portion 179 of the articularsurface and/or bone beneath remaining). This embodiment may beparticularly beneficial since it further minimizes the potential foraccidentally damaging the nerve bundle. However, the system and methodaccording to the present disclosure may also allow for the secondexcision site 176 to extend completely across the articular surface.

Turning now to FIGS. 21-23, side, frontal and perspective views of oneembodiment of a femoral implant 180 consistent with the presentdisclosure are generally illustrated. In the illustrated embodiment, thefemoral implant 180 includes a first portion 182 a and a second portion182 b. As generally described in greater detail herein, the firstportion 182 a may generally correspond to a portion of the femoralcondyle 106 a proximate the first excision site 141 and the secondportion 182 b may generally correspond to a portion of the femoralcondyle 106 a proximate the second excision site 176. As shown, thefirst and second portions 182 a, 182 b may be formed from single,unitary structure. It should be noted that in other embodiments, thefirst and second portions 182 a, 182 b may be separate components andmay be joined to one another by any known means generally understood byone skilled in the art so as to form the femoral implant 180.

The first and second portions 182 a, 182 b may include a load bearingsurface 184 and a bone facing surface 186. The load bearing surface 184of the first portion 182 a may have a surface contour/geometrysubstantially corresponding to the contour/geometry of the removedfemoral articular surface and/or bone of the first excision site 141.Similarly, the load bearing surface 184 of the second portion 182 b mayhave a surface contour/geometry substantially corresponding to thecontour/geometry of the removed femoral articular surface and/or bone ofthe second excision site 176. As such, the load bearing surface 184 maygenerally correspond to the patient's original articular surface 104 ofthe femoral condyle 106 a, as seen in FIG. 9, for example. Thecontour/geometry of the load bearing surface 184 may be based on aplurality of measurements taken of the patient's femoral articularsurface.

The bone facing surface 186 of the first portion 182 a of the femoralimplant 180 may have an overall contour/geometry generally correspondingto the contour/geometry of the base portion 177 of the first excisionsite 141. Similarly, the bone facing surface 186 of the second portion182 b may have an overall contour/geometry generally corresponding tothe contour/geometry of the base portion 178 of the second excision site176. The bone facing surface 186 may include one or more reliefcavities, pockets and/or cross-cuts (not shown) configured to enhancesecuring the implant 180 to the bone 102. The relief cavities may beconfigured to allow bone regrowth around a portion of the implant 180and/or promote cement adhesion.

The bone facing surface 186 may optionally include indicia (not shown)representing either inferior and/or superior sides of the implant 180 aswell as the size of the implant 180. These indicia may be used by thesurgeon to properly align the implant 180 along the inferior-superiorand medial-lateral planes within the first and second excision sites.

The bone facing surface 186 may also optionally include one or morerims, ribs or protrusions 190 extending generally away from the bonefacing surface 184, for example, as clearly illustrated in FIG. 23. Asshown, the rims 190 may extend along the entire periphery of the implant180. The rims 190 may include a superior rim 190 a disposed proximatethe first portion 182 a of the implant 180 and/or an inferior rim 190 bdisposed proximate the second portion 182 b of the implant 180. Thefirst and second excisions sites 141, 176 corresponding to the rims 190may be include a contour configured to receive the rims 190.

The implant 180 may further include a fixation member 188 coupled to andextending away from the bone facing surface 186. The fixation member 188may be configured to be received in the longitudinal bore 153 formed inthe articular surface 104 and secure the implant 180 to the femoralcondyle 106 a. The fixation member 188 may optionally be configured toengage with another fixation element (not shown) configured to besecured into the bore 153 of the patient's bone. For example, the otherfixation element may include a post having a threaded outer regionconfigured to engage with an interior surface of the bore 153. The postmay include a female opening configured to frictionally engage with thefixation member 188.

FIG. 24A is a side view of the femoral implant 180 aligned with thefemoral condyle 106 a (e.g. fixation member 188 is generally alignedwith bore 153 along reference axis A). FIG. 24B is a side view of thefemoral implant 180 coupled to the first and second excision sites 141,176 formed in the femoral condyle 106 a consistent with the presentdisclosure. An adhesive (such as, but not limited to, bone cement or thelike) may be applied to the bone facing surface 186 and may securelycoupled the implant 180 to the bone 102. When coupling the implant 180to the femoral condyle 106 a, the bore 153 may be shaped and/or sized toreceive and frictionally engage the fixation member 188 of the implant180 and the first and second portions 182 a, 182 b may be receivedwithin the first and second excision sites 141, 176.

As may be appreciated from FIGS. 7 and 24B, a femoral implant consistentwith at least one embodiment of the present disclosure may be configuredto cooperate with a tibial implant consistent with at least oneembodiment of the present disclosure. For example, the load bearingsurface 184 of the femoral implant 180 may be configured to matinglyengage and cooperate with the load bearing surface 72 of the tibialimplant 70, thereby allowing flexing of the knee.

According to one aspect, the present disclosure features an implantresection system for preparing an implant site to replace a defect in anarticular surface of a first bone. The implant resection system includesa first guide configured to be coupled to a first bone. The first guideincludes a body portion having at least one channel defined on a portionthereof. The channel is configured to extend generally perpendicular toa portion of the first bone proximate to the defect. At least one pin isconfigured to be received and retained within the channel. The pin has adistal end configured to pierce the first bone and to extend and form alongitudinally disposed bore within the first bone.

According to another aspect, the present disclosure features a methodfor preparing an implant site to replace a defect in an articularsurface of a bone. The method includes securing a first guide to a bone.The first guide includes a body portion having at least one channeldefined on a portion thereof. The channel is configured to extendgenerally perpendicular to a portion of the bone proximate to saiddefect. The method further includes advancing at least one pin along thechannel and into the bone and forming a longitudinally disposed borewithin the bone. The method further includes removing the pin from thebone and securing a second guide generally perpendicular to the boneproximate to the defect. The second guide includes a body portion havinga handle member disposed at one end and a first passageway and a secondpassageway defined on an opposing end. The passageways each define agenerally cylindrical core pathway configured to extend generallyperpendicular to the bone. The method further includes forming anexcision site on the bone.

While the principles of the present disclosure have been describedherein, it is to be understood by those skilled in the art that thisdescription is made only by way of example and not as a limitation as tothe scope of the invention. The features and aspects described withreference to particular embodiments disclosed herein are susceptible tocombination and/or application with various other embodiments describedherein. Such combinations and/or applications of such described featuresand aspects to such other embodiments are contemplated herein. Otherembodiments are contemplated within the scope of the present inventionin addition to the exemplary embodiments shown and described herein.Modifications and substitutions by one of ordinary skill in the art areconsidered to be within the scope of the present invention, which is notto be limited except by the following claims.

All definitions, as defined and used herein, should be understood tocontrol over dictionary definitions, definitions in documentsincorporated by reference, and/or ordinary meanings of the definedterms.

The indefinite articles “a” and “an,” as used herein in thespecification and in the claims, unless clearly indicated to thecontrary, should be understood to mean “at least one.”

The phrase “and/or,” as used herein in the specification and in theclaims, should be understood to mean “either or both” of the elements soconjoined, i.e., elements that are conjunctively present in some casesand disjunctively present in other cases. Other elements may optionallybe present other than the elements specifically identified by the“and/or” clause, whether related or unrelated to those elementsspecifically identified, unless clearly indicated to the contrary.

All references, patents and patent applications and publications thatare cited or referred to in this application are incorporated in theirentirety herein by reference.

Additional disclosure in the format of claims is set forth below:

What is claimed is:
 1. An implant resection system for preparing animplant site to replace a defect in an articular surface of a firstbone, said implant resection system comprising: a first guide configuredto be coupled to a first bone, said first guide comprising: a bodyportion having at least one channel defined on a portion thereof, saidchannel configured to extend generally perpendicular to a portion ofsaid first bone proximate to said defect; an arm extending outwardlyfrom a distal face of said body portion of said first guide; and a spoondisposed about a distal end of said arm, said spoon configured to bedisposed between said articular surface of said first bone and anarticular surface of a second cooperating bone; at least one pinconfigured to be received and retained within said channel, said pinhaving a distal end configured to pierce said first bone and to extendand form a longitudinally disposed bore within said first bone; and animplant comprising: a load bearing surface having a contoursubstantially corresponding to a contour of said articular surfacecorresponding to said implant site; and a bone facing surface having acontour substantially corresponding to a contour of said implant siteformed in said first bone.
 2. The implant resection system of claim 1,wherein said spoon further comprises a generally convex base portionconfigured to abut against said articular surface of said cooperatingbone and a generally concave upper portion configured to abut againstsaid articular surface of said first bone.
 3. The implant resectionsystem of claim 1, wherein said at least one channel is configured toalign said at least one pin such that said at least one pin extends intosaid first bone and forms said bore proximate to said defect.
 4. Theimplant resection system of claim 1, further comprising: a second guideconfigured to be coupled to said first bone proximate to said defect,said second guide comprising a body portion having a handle memberdisposed at one end and a first passageway and a second passagewaydefined on an opposing end, said passageways each defining a generallycylindrical core pathway configured to extend generally outward fromsaid first bone; a rod member configured to be received within andadvanced through said first passageway and into a portion of said borein said first bone; and a drill bit configured to be received within andextend through said second passageway and proximate to said defect insaid first bone.
 5. The implant resection system of claim 4, whereinsaid second guide is configured to move from a first position to asecond position relative said first bone and said defect.
 6. The implantresection system of claim 5, wherein said drill bit is adjacent saidfirst bone proximate to said defect when said second guide is in saidfirst position.
 7. The implant resection system of claim 5, wherein saidrod member provides a generally longitudinal axis generallyperpendicular to said first bone about which said body portion of saidsecond guide rotates when said second guide moves from said firstposition to said second position.
 8. The implant resection system ofclaim 7, wherein said drill bit is configured to rotate about said axisof said rod member and remove a portion of articular surface said firstbone to define an excision site when said second guide moves from saidfirst position to said second position.
 9. The implant resection systemof claim 1, wherein said bone facing surface further comprises aplurality of relief cavities configured secure said implant to saidbone.
 10. The implant resection system of claim 1, wherein said implantcomprises an upper portion configured to be secured to a lower portion,said upper portion comprising said load bearing surface and said lowerportion comprising said bone facing surface.
 11. The implant resectionsystem of claim 1, wherein said first bone is a femur and said secondbone is a tibia.
 12. A method for preparing an implant site to replace adefect in an articular surface of a bone, said method comprising:securing a first guide to a bone, said first guide comprising a bodyportion having at least one channel defined on a portion thereof, saidchannel configured to extend generally perpendicular to a portion ofsaid bone proximate to said defect; advancing at least one pin alongsaid channel and into said bone and forming a longitudinally disposedbore within said bone; removing said pin from said bone; securing asecond guide generally perpendicular to said bone proximate to saiddefect using a rod member received within and advanced through a firstpassageway and into a portion of said bore in said bone, said secondguide comprising a body portion having a handle member disposed at oneend and said first passageway and a second passageway defined on anopposing end, said passageways each defining a generally cylindricalcore pathway configured to extend generally perpendicular to said bone;and advancing a drill bit partially through said second passagewayproximate to said defect in said bone; and moving said second guide froma first position to a second position relative said bone and said defectto form an excision site on said bone.
 13. The method of claim 12,wherein said rod member provides a generally longitudinal axis generallyperpendicular to said bone about which said body portion of said secondguide rotates when said second guide moves from said first position tosaid second position.
 14. The method of claim 13, wherein said drill bitrotates about said axis of said rod member and removes a portion ofarticular surface said bone to form said excision site when said secondguide moves from said first position to said second position.
 15. Themethod of claim 12, wherein said bone is a femoral condyle.